﻿using System;
using System.Collections;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Reflection;
namespace GK2010.Utility
{
    public class JsonHelper
    {
        /// <summary>
        /// List转成json 
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="jsonName"></param>
        /// <param name="list"></param>
        /// <returns></returns>
        public static string ListToJson<T>(IList<T> list, string jsonName)
        {
            StringBuilder Json = new StringBuilder();
            if (string.IsNullOrEmpty(jsonName))
                jsonName = list[0].GetType().Name;

            Json.Append("{\"" + jsonName + "\":[");

            if (list.Count > 0)
            {
                for (int i = 0; i < list.Count; i++)
                {
                    T obj = Activator.CreateInstance<T>();

                    PropertyInfo[] pi = obj.GetType().GetProperties();

                    Json.Append("{");

                    for (int j = 0; j < pi.Length; j++)
                    {

                        Type type = pi[j].GetValue(list[i], null).GetType();

                        Json.Append("\"" + pi[j].Name.ToString() + "\":" + StringFormat(pi[j].GetValue(list[i], null).ToString(), type));

                        if (j < pi.Length - 1)
                        {
                            Json.Append(",");
                        }
                    }
                    Json.Append("}");

                    if (i < list.Count - 1)
                    {

                        Json.Append(",");

                    }
                }

            }

            Json.Append("]}");

            return Json.ToString();

        }


        /// <summary>
        /// List转成json 
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="list"></param>
        /// <returns></returns>
        public static string ListToJson<T>(IList<T> list)
        {
            object obj = list[0];
            return ListToJson<T>(list, obj.GetType().Name);
        }


        /// <summary> 
        /// 对象转换为Json字符串 
        /// </summary> 
        /// <param name="jsonObject">对象</param> 
        /// <returns>Json字符串</returns> 
        public static string ToJson(object jsonObject)
        {
            try
            {
                StringBuilder jsonString = new StringBuilder();
                jsonString.Append("{");
                PropertyInfo[] propertyInfo = jsonObject.GetType().GetProperties();

                for (int i = 0; i < propertyInfo.Length; i++)
                {
                    object objectValue = propertyInfo[i].GetGetMethod().Invoke(jsonObject, null);

                    if (objectValue == null)
                    {
                        continue;
                    }

                    StringBuilder value = new StringBuilder();

                    if (objectValue is DateTime || objectValue is Guid || objectValue is TimeSpan)
                    {

                        value.Append("\"" + objectValue.ToString() + "\"");

                    }

                    else if (objectValue is string)
                    {

                        value.Append("\"" + objectValue.ToString() + "\"");

                    }

                    else if (objectValue is IEnumerable)
                    {

                        value.Append(ToJson((IEnumerable)objectValue));

                    }

                    else
                    {

                        value.Append("\"" + objectValue.ToString() + "\"");

                    }

                    jsonString.Append("\"" + propertyInfo[i].Name + "\":" + value + ","); ;

                }

                return jsonString.ToString().TrimEnd(',') + "}";

            }

            catch (Exception ex)
            {

                throw ex;

            }

        }



        /// <summary> 

        /// 对象集合转换Json 

        /// </summary> 

        /// <param name="array">集合对象</param> 

        /// <returns>Json字符串</returns> 

        public static string ToJson(IEnumerable array)
        {

            string jsonString = "[";

            foreach (object item in array)
            {

                jsonString += ToJson(item) + ",";

            }

            jsonString.Remove(jsonString.Length - 1, jsonString.Length);

            return jsonString + "]";

        }



        /// <summary> 

        /// 普通集合转换Json 

        /// </summary> 

        /// <param name="array">集合对象</param> 

        /// <returns>Json字符串</returns> 

        public static string ToArrayString(IEnumerable array)
        {

            string jsonString = "[";

            foreach (object item in array)
            {

                jsonString = ToJson(item.ToString()) + ",";

            }

            jsonString.Remove(jsonString.Length - 1, jsonString.Length);

            return jsonString + "]";

        }



        /// <summary> 

        /// Datatable转换为Json 

        /// </summary> 

        /// <param name="table">Datatable对象</param> 

        /// <returns>Json字符串</returns> 

        public static string ToJson(DataTable dt)
        {

            StringBuilder jsonString = new StringBuilder();

            jsonString.Append("[");

            DataRowCollection drc = dt.Rows;

            for (int i = 0; i < drc.Count; i++)
            {

                jsonString.Append("{");

                for (int j = 0; j < dt.Columns.Count; j++)
                {

                    string strKey = dt.Columns[j].ColumnName;

                    string strValue = drc[i][j].ToString();

                    Type type = dt.Columns[j].DataType;

                    jsonString.Append("\"" + strKey + "\":");

                    strValue = StringFormat(strValue, type);

                    if (j < dt.Columns.Count - 1)
                    {

                        jsonString.Append(strValue + ",");

                    }

                    else
                    {

                        jsonString.Append(strValue);

                    }

                }

                jsonString.Append("},");

            }

            jsonString.Remove(jsonString.Length - 1, 1);

            jsonString.Append("]");

            return jsonString.ToString();

        }



        /// <summary>

        /// DataTable转成Json 

        /// </summary>

        /// <param name="jsonName"></param>

        /// <param name="dt"></param>

        /// <returns></returns>

        public static string ToJson(DataTable dt, string jsonName)
        {

            StringBuilder Json = new StringBuilder();

            if (string.IsNullOrEmpty(jsonName))

                jsonName = dt.TableName;

            Json.Append("{\"" + jsonName + "\":[");

            if (dt.Rows.Count > 0)
            {

                for (int i = 0; i < dt.Rows.Count; i++)
                {

                    Json.Append("{");

                    for (int j = 0; j < dt.Columns.Count; j++)
                    {

                        Type type = dt.Rows[i][j].GetType();

                        Json.Append("\"" + dt.Columns[j].ColumnName.ToString() + "\":" + StringFormat(dt.Rows[i][j].ToString(), type));

                        if (j < dt.Columns.Count - 1)
                        {

                            Json.Append(",");

                        }

                    }

                    Json.Append("}");

                    if (i < dt.Rows.Count - 1)
                    {

                        Json.Append(",");

                    }

                }

            }

            Json.Append("]}");

            return Json.ToString();

        }



        /// <summary> 

        /// DataReader转换为Json 

        /// </summary> 

        /// <param name="dataReader">DataReader对象</param> 

        /// <returns>Json字符串</returns> 

        public static string ToJson(IDataReader dataReader)
        {

            StringBuilder jsonString = new StringBuilder();

            jsonString.Append("[");



            while (dataReader.Read())
            {

                jsonString.Append("{");

                for (int i = 0; i < dataReader.FieldCount; i++)
                {

                    Type type = dataReader.GetFieldType(i);

                    string strKey = dataReader.GetName(i);

                    string strValue = dataReader[i].ToString();

                    jsonString.Append("\"" + strKey + "\":");

                    strValue = StringFormat(strValue, type);

                    if (i < dataReader.FieldCount - 1)
                    {

                        jsonString.Append(strValue + ",");

                    }

                    else
                    {

                        jsonString.Append(strValue);

                    }

                }

                jsonString.Append("},");

            }

            dataReader.Close();

            jsonString.Remove(jsonString.Length - 1, 1);

            jsonString.Append("]");

            if (jsonString.Length == 1)
            {

                return "[]";

            }

            return jsonString.ToString();

        }



        /// <summary> 

        /// DataSet转换为Json 

        /// </summary> 

        /// <param name="dataSet">DataSet对象</param> 

        /// <returns>Json字符串</returns> 

        public static string ToJson(DataSet dataSet)
        {

            string jsonString = "{";

            foreach (DataTable table in dataSet.Tables)
            {

                jsonString += "\"" + table.TableName + "\":" + ToJson(table) + ",";

            }

            jsonString = jsonString.TrimEnd(',');

            return jsonString + "}";

        }



        /// <summary>

        /// 过滤特殊字符

        /// </summary>

        /// <param name="s"></param>

        /// <returns></returns>

        private static string String2Json(String s)
        {

            StringBuilder sb = new StringBuilder();

            for (int i = 0; i < s.Length; i++)
            {

                char c = s.ToCharArray()[i];

                switch (c)
                {

                    case '\"':

                        sb.Append("\\\""); break;

                    case '\\':

                        sb.Append("\\\\"); break;

                    case '/':

                        sb.Append("\\/"); break;

                    case '\b':

                        sb.Append("\\b"); break;

                    case '\f':

                        sb.Append("\\f"); break;

                    case '\n':

                        sb.Append("\\n"); break;

                    case '\r':

                        sb.Append("\\r"); break;

                    case '\t':

                        sb.Append("\\t"); break;

                    default:

                        sb.Append(c); break;

                }

            }

            return sb.ToString();

        }



        /// <summary>

        /// 格式化字符型、日期型、布尔型

        /// </summary>

        /// <param name="str"></param>

        /// <param name="type"></param>

        /// <returns></returns>

        private static string StringFormat(string str, Type type)
        {

            if (type != typeof(string) && string.IsNullOrEmpty(str))
            {

                str = "\"" + str + "\"";

            }

            else if (type == typeof(string))
            {

                str = String2Json(str);

                str = "\"" + str + "\"";

            }

            else if (type == typeof(DateTime))
            {

                str = "\"" + str.Split(' ')[0] + "\"";

            }
            else if (type == typeof(bool))
            {

                str = str.ToLower();

            }
            return str;

        }


    }
}
